In Century Rain by Alastair Reynolds, people seed the oceans and the upper atmosphere with tons of tiny floating machines, "invisible to the eye, harmless to people." They controlled the weather and fixed the climate by reflecting radiation here or absorbing it there. The machines made clouds appear and disappear and controlled ocean currents. And it works — for a while. The climate starts returning to pre-2050 conditions. But then the nanomachines stop obeying orders, and even create an obscene symbol off the Bay Of Biscay "that had to be airbrushed out of every satellite image." The scientists try to release even smarter nanomachines to deal with the first batch of nanomachines and — well, you can guess how well that turns out.

2: A ring of ice.

In the Stanislaw Lem novel Fiasco, scientists launch an artificial ring of ice into the atmosphere of the planet Quinta to reduce temperatures so the oceans will recede and more land mass will be available. The mass of the ice ring is equal to around 1 percent of the oceans' volume. The protagonists speculate that the ring was created by causing lightning in the upper atmosphere to create a kind of ice rail-gun that could shoot the ice up into orbit. This being a Stanislaw Lem novel, the whole thing falls apart due to political wrangling before it can be completed, so huge chunks of ice rain down onto the planet's equator in a never-ending torrent.

3: Use special bacteria.

In the story "Noah's Ark" by Narendra Desirazu, we find bacteria on Mars, with bizarre properties — it hibernates just below the freezing point of water, but when the water melts, the bacteria goes into frantic activity to get the water to refreeze. So scientists struggle with the effort to introduce the bacteria only to the icecaps and other areas where they want to reverse melting — without letting it get into, say, our oceans and stuff. Luckily, there's a happy but "ambivalent" ending.

4: Build a giant sunshade around the Earth.

We build huge space elevators and a massive sunshade in The Night Sessions by Ken MacLeod, causing the dawn light to look all trippy:

The dawn sky glowed innumerable shades of green, from lemon to duck-egg to almost blue, like the background colour in a Hindu painting, and turned slowly to a pure deep blue over ten minutes or more as he watched. He dozed again.

Also, Arthur C. Clarke's Fountains Of Paradise includes a ring of satellites and space stations linked together around a planet's equator by cables and other connectors, which becomes an unbroken wheel of tremendous stability — which presumably can reflect a lot of sunlight. And in Clarke's Childhood's End, the Overlords are able to use polarized fields to "make the sun go out" for a particular region of South Africa, to punish the residents for depriving the white minority of civil rights. And in Venus Of Dreams by Pamela Sargent, colonists cool the planet Venus by using a giant Parasol to shade the planet, plus bombarding the planet with ice asteroids.

5: Take Earth further away from the sun.

The Futurama episode "Crimes Of The Hot" is like a smorgasbord of global-warming solutions. We learn that humans stopped global warming in the 21st century by bombarding the oceans with ice from space. And now that the planet is heating up again, due to the emissions from unsafe robots, there are a few solutions, including a giant space mirror (which goes awry) and shutting down all the robots. But in the end, the easiest solution is to have all the robots emit their exhaust at once, sending the planet further away from the sun — and giving us an extra week in each year, which can be Robot Party Week!

And in the novel The Circle: A Science Fiction Thriller by Harold R. Watson, the High Rulers Of Earth decide to haul the planet away from the sun to put it into a deep freeze for one year. At the end of that time, they'll return Earth to its original orbit. As some of the planet's icy covering melts, it'll have the effect of restoring the ozone layer, and after about five years, enough vegetation will have grown to make the planet habitable again. Suuuure.

Dear Abbey is a radical, long-range plan for saving the environment that will make Ted Kaczynski look like Mother Teresa. It involves an alarmingly complex but theoretically possible piece of genetic engineering that will, let us say, severely inhibit the ability of humans to degrade the environment. Severe being the operative modifier. You can't call it terrorism because no one will be killed, directly at least, and no one will even know for sure what is happening until it has been operating for at least a decade, by which time it will be too late to undo it. The human cost will be high but not nearly as high as the cost of doing nothing, or of simply continuing with the kind of pointless stunts for which the environmental movement is known.

7: Restart the Gulf Stream

Kim Stanley Robinson is the champion of depicting environmental disasters and geo-hacking projects, and his environmental thrillers Forty Signs Of Rain and Fifty Degrees Below deal with the disastrous effects of global warming. Among other things, Fifty Degrees includes scientists trying to restart the stalled Gulf Stream. The ice caps melt completely, and in the winter, Washington, D.C. hits fifty degrees below. So an enormous fleet of ships ventures out to dump millions of tons of ice into the ocean in the hopes of rebooting the Gulf Stream. A fleet of 3,500 oil tankers is available to transport the salt, and five hundred million metric tons of salt is needed — about two years' worth of total world production.

8: Shut down all our technology

I'm still not entirely sure what happened at the end of last year's "remake" (quotation marks are necessary here) of The Day The Earth Stood Still. Keanu/Klaatu was going to unleash nanomachines to disassemble everything on Earth, because that would save the planet. You know that makes sense! And then he changed his mind and did some kind of EMP-ish thing that made all electricity go out and all technology stop working. So the human race was allowed to survive, but with no technology. Keanu is merciful! All hail Keanu!

9: Open a big hole.

Global warming? No problem! Just open a dimensional gateway and pump all the extra heat somewhere else. That's the scheme that a science whiz comes up with in the Stargate Atlantis episode "Brain Storm" (featuring Bill Nye the Science Guy, among other luminaries.) Of course, it all goes horribly wrong and the gathering of eminent scientists is in danger of freezing to death.

Also, in the Syfy movie Lost City Raiders, the world is flooded due to global warming. And the Catholic Church has the answer — an ancient hole in the ground, which will drain off all the excess water to... somewhere. But you need to find the secret hidden keys to open it. It all makes perfect sense!

10: Kill the aliens who are causing the problem in the first place.

But of course, you know deep down that global warming can't really be the result of our own completely harmless activities. There must be aliens behind it — probably evil dinosaur aliens. In the Syfy original TV movie, Heatstroke, it turns out that dinosaur people have been secretly working to pump out greenhouse gases to raise our planet's temperature and prepare the way for their invasion. But the U.S. government knows about this and sends a secret taskforce (why not a whole army? Budget constraints, I guess) to stop them. The aliens are operating on a tropical island, where an ex-swimsuit model just happens to be shooting a new calendar. It's like synergy! Oh, and there's also The Arrival directed by David Twohy, where Charlie Sheen discovers that weird double-jointed aliens are producing greenhouse gases to mess us up and transform our planet. Good thing it's Charlie Sheen, then.

Oh, and the Silurians in Doctor Who And The Silurians also have a similar idea about raising the planet's temperature, but they don't get very far with it.

Additional reporting by Alexis Brown. This post also would have been a lot harder to write without the never-ending awesomeness that is Technovelgy.com.